Note: This doc is meant to supply steering on the suitable use of testing and doesn’t dictate the willpower of fee choices or insurance coverage protection of such testing for individuals residing within the United States, besides as could also be in any other case referenced (or prescribed) by one other entity or federal or state company.
Revisions had been made on July 2, 2020, to:
- Added screening to potential testing sorts
- Removed examples – please check with setting particular steering
This doc supplies a abstract of concerns and present Centers for Disease Control and Prevention (CDC) suggestions concerning SARS-CoV-2 testing technique. The CDC suggestions for SARS-CoV-2 testing have been developed based mostly on what’s at the moment identified about COVID-19 and are topic to alter as extra data turns into accessible.
Recommendations for Viral Testing, Specimen Collection, and Reporting
Authorized assays for viral testing embody people who detect SARS-CoV-2 nucleic acid or antigen. Viral (nucleic acid or antigen) tests examine samples from the respiratory system (akin to nasal swabs) and decide whether or not an an infection with SARS-CoV-2, the virus that causes COVID-19, is current. Viral assessments are beneficial to diagnose acute an infection. Some assessments are point-of-care assessments, that means outcomes could also be accessible on the testing website in lower than an hour. Other assessments should be despatched to a laboratory to research, a course of that will take 1-2 days as soon as obtained by the lab. Testing the identical particular person greater than as soon as in a 24-hour interval just isn’t beneficial.
For extra data on testing for COVID-19 see the Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens and Biosafety FAQs for dealing with and processing specimens from potential circumstances.
Recommendations for Antibody Testing
CDC doesn’t at the moment suggest using antibody testing as the only real foundation for analysis of acute an infection, and antibody assessments are usually not licensed by FDA for such diagnostic functions. In sure conditions, serologic assays could also be used to support clinical assessment of individuals who current late of their sicknesses when used along with viral detection assessments. In addition, if an individual is suspected to have post-infectious syndrome (e.g., Multisystem Inflammatory Syndrome in Children) attributable to SARS-CoV-2 an infection, serologic assays could also be used.
Serologic assays for SARS-CoV-2, now broadly accessible, can play an vital position in understanding the transmission dynamic of the virus within the common inhabitants and figuring out teams at increased danger for an infection. Unlike viral direct detection strategies, akin to nucleic acid amplification or antigen detection assessments that may detect acutely contaminated individuals, antibody assessments assist decide whether or not the person being examined was beforehand contaminated—even when that particular person by no means confirmed signs.
Categories for SARS-CoV-2 Testing
This doc describes 5 populations for which SARS-CoV-2 testing with viral tests (i.e., nucleic acid or antigen assessments) is acceptable:
Generally, viral testing for SARS-CoV-2 is taken into account to be diagnostic when performed amongst people with signs per COVID-19 or amongst asymptomatic people with identified or suspected current publicity to SARS-CoV-2 to regulate transmission, or to find out decision of an infection. Viral testing is screening when performed amongst asymptomatic people with out identified or suspected publicity to SARS-CoV-2 for early identification, and surveillance when performed amongst asymptomatic people to detect transmission sizzling spots or characterize illness tendencies.
Recommended testing for people with indicators or signs per COVID-19
CDC recommends utilizing authorized nucleic acid or antigen detection assaysexternal icon which have obtained an FDA EUA to check individuals with signs when there’s a concern of potential COVID-19. Tests must be utilized in accordance with the licensed labeling; suppliers must be acquainted with the assessments’ efficiency traits and limitations.
Clinicians ought to use their judgment to find out if a affected person has indicators or symptoms appropriate with COVID-19 and whether or not the affected person must be examined. Most sufferers with confirmed COVID-19 have developed fever and/or signs of acute respiratory sickness (e.g., cough) however some contaminated sufferers might current with other symptoms (e.g., altered smell or taste) as well. Clinicians are inspired to think about testing for different causes of respiratory sickness, for instance influenza, along with testing for SARS-CoV-2 relying on affected person age, season, or scientific setting; detection of 1 respiratory pathogen (e.g., influenza) doesn’t exclude the potential for co-infection with SARS-CoV-2. Because signs and shows could also be totally different in youngsters, think about referencing the CDC tips for COVID-19 in neonates and for Multisystem Inflammatory Syndrome in Children (MIS-C).
The severity of symptomatic sickness because of an infection with SARS-CoV-2 might differ from individual to individual. Among individuals with intensive and shut contact to vulnerable populations (e.g., healthcare personnel [HCP]), even gentle indicators and signs (e.g., sore throat) of a potential SARS-CoV-2 an infection ought to immediate consideration for testing. Additional data is on the market in CDC’s Interim Guidance on Testing Healthcare Personnel for SARS-CoV-2.
Recommended testing for asymptomatic people with identified or suspected publicity to SARS-CoV-2 to regulate transmission
Testing is beneficial for all close contactspdf icon of individuals with SARS-CoV-2 an infection. Because of the potential for asymptomatic and pre-symptomatic transmission, it is crucial that contacts of people with SARS-CoV-2 an infection be rapidly recognized and examined.
In some settings, broader testing, past shut contacts, is beneficial as part of a technique to regulate transmission of SARS-CoV-2. This consists of high-risk settings which have potential for fast and widespread dissemination of SARS-CoV-2 or through which populations in danger for extreme illness might change into uncovered. Expanded testing may embody testing of people on the identical unit or shift as somebody with SARS-CoV-2 an infection, and even testing all people inside a shared setting (e.g., facility-wide testing).
Recommended testing for asymptomatic people with out identified or suspected SARS-CoV-2 publicity for early identification in particular settings
Certain settings can expertise fast unfold of SARS-CoV-2. This is especially true for settings with susceptible populations in shut quarters for prolonged durations of time.
Local, territorial, tribal, and state health departments might help with knowledgeable decision-making about testing at these or different settings. Before testing giant numbers of asymptomatic people with out identified or suspected publicity, facility management ought to have a plan in place for the way they are going to modify operations based mostly on check outcomes.
- Approaches for early identification of asymptomatic people embody, preliminary testing of everybody within the setting, periodic (e.g., weekly) testing of everybody within the setting, and testing of latest or returning entrants into the setting.
Recommended testing to find out decision of an infection with SARS-CoV-2
A test-based technique, which requires serial assessments and enchancment of signs, can be utilized, as an alternative choice to a symptom-based or time-based technique, to find out when an individual with SARS-CoV-2 an infection not requires isolation or work exclusion. This technique may very well be thought-about in three conditions:
Public well being surveillance for SARS-CoV-2
Testing is a elementary a part of the United States SARS-CoV-2 Surveillance Plan, which makes use of a number of surveillance techniques and epidemiology networks to watch the development and affect of SARS-CoV-2 unfold within the United States.
Tests are utilized in neighborhood, outpatient, and hospital-based surveillance techniques to establish circumstances of SARS-CoV-2 an infection. These knowledge assist establish areas of ongoing circulation, decide tendencies in illness by location, present perception into the affect of the illness over time and by location, and inform illness forecasts.